apply another quickfix by komh

really, getdrvwd should be passed an Xstring (probably with Xinit0 in
the callers), especially as one caller already didn’t update ldestlen
properly… (but not tonight as I’ve really got no head for that left)

misc.c

@@ -32,7 +32,7 @@
 #include <grp.h>
 #endif
 
-__RCSID("$MirOS: src/bin/mksh/misc.c,v 1.287 2017/10/14 20:11:30 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/misc.c,v 1.288 2017/10/15 20:21:51 tg Exp $");
 
 #define KSH_CHVT_FLAG
 #ifdef MKSH_SMALL
@@ -2189,6 +2189,7 @@ c_cd(const char **wp)
 	}
 
 #ifdef MKSH_DOSPATH
+	tryp = NULL;
 	if (mksh_drvltr(dir) && !mksh_cdirsep(dir[2]) &&
 	    !getdrvwd(&tryp, ord(*dir))) {
 		dir = shf_smprintf(Tf_sss, tryp,